Claude-skill-registry env-config-validator

Validate environment configuration files across local, staging, and production environments. Ensure required secrets, database URLs, API keys, and public variables are properly scoped and set. Use this skill when setting up environments, validating configuration, checking for missing secrets, auditing environment variables, ensuring proper scoping of public vs private vars, or troubleshooting environment issues. Trigger terms include env, environment variables, secrets, configuration, .env file, environment validation, missing variables, config check, NEXT_PUBLIC, env vars, database URL, API keys.

install
source · Clone the upstream repo
git clone https://github.com/majiayu000/claude-skill-registry
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/data/env-config-validator" ~/.claude/skills/majiayu000-claude-skill-registry-env-config-validator && rm -rf "$T"
manifest: skills/data/env-config-validator/SKILL.md
source content

Environment Configuration Validator

Validate

.env
files across local, staging, and production environments. Ensure all required secrets, database URLs, API keys, and public variables are properly scoped, set, and secure.

Core Capabilities

1. Validate Environment Files

To validate environment configuration:

  • Parse
    .env
    ,
    .env.local
    ,
    .env.production
    , etc.
  • Check for required variables
  • Verify variable naming conventions
  • Detect security issues (exposed secrets, weak values)
  • Use
    scripts/validate_env.py
    for automated validation

2. Check Variable Scoping

Ensure proper scoping of environment variables:

  • Public variables (
    NEXT_PUBLIC_*
    ): Accessible in browser
  • Private variables: Server-side only
  • Database credentials: Never exposed to client
  • API keys: Properly scoped based on usage

3. Cross-Environment Validation

Compare configurations across environments:

  • Identify missing variables in staging/production
  • Check for environment-specific overrides
  • Ensure consistency in variable names
  • Validate environment-specific values (URLs, keys)

4. Security Auditing

Detect security vulnerabilities in environment configuration:

  • Exposed secrets in public variables
  • Weak or default values
  • Hardcoded credentials in code
  • Missing required security variables (JWT secrets, encryption keys)

Validation Rules

Required Variables

Ensure these categories of variables are present:

  1. Database Connection

    • DATABASE_URL
      or equivalent
    • Connection pool settings (optional)
  2. Authentication

    • JWT_SECRET
      or
      AUTH_SECRET
    • OAuth credentials (if using OAuth)
    • Session secrets
  3. External APIs

    • Third-party API keys
    • Service endpoints
    • Rate limiting tokens
  4. Application Config

    • NODE_ENV
    • NEXT_PUBLIC_APP_URL
      or
      APP_URL
    • Feature flags (optional)
  5. Email/Notifications (if used)

    • SMTP credentials
    • Email service API keys

Naming Conventions

Follow Next.js environment variable conventions:

  • Public variables:

    NEXT_PUBLIC_*
    prefix

    • Example:
      NEXT_PUBLIC_API_URL
    • Accessible in browser
    • Never put secrets here
  • Private variables: No prefix

    • Example:
      DATABASE_URL
      ,
      API_SECRET
    • Server-side only
    • Safe for secrets
  • Naming style:

    SCREAMING_SNAKE_CASE

    • Example:
      DATABASE_URL
      ,
      JWT_SECRET
      ,
      STRIPE_API_KEY

Security Rules

  1. Never expose secrets in public variables

    • [ERROR]
      NEXT_PUBLIC_DATABASE_URL
    • [OK]
      DATABASE_URL
  2. Database URLs must be private

    • [ERROR]
      NEXT_PUBLIC_DB_URL
    • [OK]
      DATABASE_URL
  3. API keys scoping

    • Client-side API keys →
      NEXT_PUBLIC_*
      (e.g., Google Maps)
    • Server-side API keys → No prefix (e.g., Stripe secret)
  4. No hardcoded secrets in code

    • Use environment variables for all secrets
    • Never commit
      .env.local
      or
      .env.production
  5. Strong secrets

    • JWT/session secrets: minimum 32 characters
    • Use cryptographically random values
    • No default or example values in production

Validation Script

Use

scripts/validate_env.py
to automate validation:

# Validate current .env file
python scripts/validate_env.py

# Validate specific file
python scripts/validate_env.py --file .env.production

# Compare multiple environments
python scripts/validate_env.py --compare .env.local .env.production

# Check against required variables template
python scripts/validate_env.py --template .env.example

The script checks:

  • Required variables are present
  • Naming conventions are followed
  • No secrets in public variables
  • No weak or default values
  • Consistent naming across environments

Common Issues and Solutions

Issue: Missing DATABASE_URL in Production

Detection: Script reports missing required variable

Solution:

# Add to .env.production
DATABASE_URL="postgresql://user:password@host:5432/dbname"

Note: Use different databases for dev/staging/prod

Issue: Secret Exposed in Public Variable

Detection: Script finds

NEXT_PUBLIC_
prefix on secret

Problem:

# [ERROR] WRONG - secret exposed to browser
NEXT_PUBLIC_API_SECRET="secret123"

Solution:

# [OK] CORRECT - server-side only
API_SECRET="secret123"

Issue: Weak JWT Secret

Detection: Script detects short or weak secret

Problem:

# [ERROR] WRONG - too short, predictable
JWT_SECRET="secret"

Solution:

# [OK] CORRECT - strong, random, 32+ characters
JWT_SECRET="a8f3d9c2e1b7f4a6d8c3e9b2f1a7d4c8e3b9f2a1d7c4e8b3f9a2d1c7e4b8f3a9"

Generate with:

node -e "console.log(require('crypto').randomBytes(32).toString('hex'))"

Issue: Inconsistent Variable Names Across Environments

Detection: Script comparison shows name mismatch

Problem:

# .env.local
DATABASE_URL="..."

# .env.production
DB_URL="..."  # [ERROR] Different name

Solution: Use consistent names

# Both files
DATABASE_URL="..."

Issue: Missing Public API URL

Detection: Client-side code fails to connect to API

Problem:

NEXT_PUBLIC_API_URL
not set

Solution:

# .env.local
NEXT_PUBLIC_API_URL="http://localhost:3000"

# .env.production
NEXT_PUBLIC_API_URL="https://api.yourapp.com"

Resource Files

scripts/validate_env.py

Python script to validate environment files, check for security issues, compare across environments, and verify against templates. Provides detailed error messages and suggestions.

references/env_best_practices.md

Comprehensive guide to environment variable management including:

  • Security best practices
  • Naming conventions
  • Scoping rules (public vs private)
  • Common patterns for different services
  • Environment-specific configuration
  • Secret rotation strategies

assets/.env.example

Template showing all required environment variables for a worldbuilding application. Use as a reference for setting up new environments or auditing existing ones.

Environment-Specific Configuration

Development (.env.local)

# Database
DATABASE_URL="postgresql://user:password@localhost:5432/worldbuilding_dev"

# Authentication
JWT_SECRET="dev-secret-change-in-production"
NEXTAUTH_URL="http://localhost:3000"
NEXTAUTH_SECRET="dev-nextauth-secret"

# Public
NEXT_PUBLIC_API_URL="http://localhost:3000"
NEXT_PUBLIC_APP_NAME="Worldbuilding App (Dev)"

# External APIs (test keys)
OPENAI_API_KEY="sk-test-..."
STRIPE_SECRET_KEY="sk_test_..."

Staging (.env.staging)

# Database
DATABASE_URL="postgresql://user:password@staging-db.com:5432/worldbuilding_staging"

# Authentication
JWT_SECRET="staging-secret-32-chars-minimum"
NEXTAUTH_URL="https://staging.yourapp.com"
NEXTAUTH_SECRET="staging-nextauth-secret"

# Public
NEXT_PUBLIC_API_URL="https://staging.yourapp.com"
NEXT_PUBLIC_APP_NAME="Worldbuilding App (Staging)"

# External APIs (test keys)
OPENAI_API_KEY="sk-test-..."
STRIPE_SECRET_KEY="sk_test_..."

Production (.env.production)

# Database
DATABASE_URL="postgresql://user:password@prod-db.com:5432/worldbuilding_prod"

# Authentication
JWT_SECRET="production-secret-use-crypto-random-32-chars-minimum"
NEXTAUTH_URL="https://yourapp.com"
NEXTAUTH_SECRET="production-nextauth-secret"

# Public
NEXT_PUBLIC_API_URL="https://api.yourapp.com"
NEXT_PUBLIC_APP_NAME="Worldbuilding App"

# External APIs (production keys)
OPENAI_API_KEY="sk-live-..."
STRIPE_SECRET_KEY="sk_live_..."

# Monitoring
SENTRY_DSN="https://..."

Best Practices

  1. Never commit secrets

    • Add
      .env.local
      ,
      .env.production
      to
      .gitignore
    • Commit
      .env.example
      as a template
  2. Use strong, random secrets

    • Minimum 32 characters for JWT/session secrets
    • Use
      crypto.randomBytes()
      or password manager
  3. Scope variables correctly

    • Public (
      NEXT_PUBLIC_*
      ): Only non-sensitive, client-accessible data
    • Private (no prefix): All secrets, credentials, server-only config
  4. Consistent naming

    • Use same variable names across all environments
    • Follow
      SCREAMING_SNAKE_CASE
      convention
  5. Environment-specific values

    • Different database URLs per environment
    • Test API keys in dev/staging, production keys in prod
    • Environment-specific URLs and endpoints
  6. Document required variables

    • Keep
      .env.example
      updated
    • Add comments explaining each variable
    • Document where to get values (API dashboard, etc.)
  7. Validate on deployment

    • Run validation script in CI/CD pipeline
    • Fail deployment if required variables missing
    • Check for security issues before deploying
  8. Rotate secrets regularly

    • Change JWT secrets periodically
    • Rotate API keys on schedule
    • Update after team member departures
  9. Use secret management tools

    • Consider Vercel Environment Variables
    • AWS Secrets Manager, HashiCorp Vault for sensitive data
    • Never store production secrets in code or comments
  10. Test environment parity

    • Staging should mirror production as closely as possible
    • Use same variable names, just different values
    • Test with production-like data

Integration with Worldbuilding App

Common environment variables for worldbuilding applications:

Database

DATABASE_URL="postgresql://..."
DATABASE_POOL_SIZE="10"  # Optional

Authentication

JWT_SECRET="..."
NEXTAUTH_URL="..."
NEXTAUTH_SECRET="..."

External APIs

# AI services (optional)
OPENAI_API_KEY="..."

# Maps (if using)
NEXT_PUBLIC_GOOGLE_MAPS_API_KEY="..."

# Image hosting (if using)
CLOUDINARY_URL="..."

Application

NODE_ENV="production"
NEXT_PUBLIC_APP_URL="https://..."
NEXT_PUBLIC_APP_NAME="Worldbuilding App"

Email (if using)

SMTP_HOST="..."
SMTP_PORT="587"
SMTP_USER="..."
SMTP_PASSWORD="..."

Consult

references/env_best_practices.md
for detailed guidance and
assets/.env.example
for a complete template.